A vehicle event detection system is typically used to notify a person of a given vehicle condition. For example, a vehicle condition detection system may be a vehicle alarm system that deters vehicle theft, prevents theft of valuables from a vehicle, deters vandalism, and protects vehicle owners and occupants. A typical vehicle event detection system, for example, includes a central processor or controller connected to vehicle sensors. The sensor, for example, may detect opening of the trunk, hood, doors, windows, and also movement of the vehicle or within the vehicle. An ultrasonic and microwave motion detector, a vibration sensor, a sound discriminator, a differential pressure sensor, a speed detector, and a switch may be used as a sensor. In addition, a radar sensor may be used to monitor the area proximate the vehicle.
The controller typically operates to give an indication in the event of triggering of a vehicle sensor. The indication may typically be a flashing of the lights, an interior visual indicator, an interior audible indicator, and/or the sounding of the vehicle horn or a siren. In addition, the vehicle fuel supply and/or ignition power may be selectively disabled based upon a condition.
The indication provided at the vehicle is important to the overall effectiveness of the event detection system. For example, a weak alarm indication may do little to deter a would-be thief or notify a person of a potential hazard or dangerous vehicle condition. A thief may also be more likely to target a vehicle when the vehicle is among hundreds of vehicles in a large parking lot, for example. In such a situation, the thief may be comforted in knowing that the alarm indication will be ignored by bystanders, since many audible alarm indications are generic. Moreover, once inside the vehicle, the thief may disable the alarm and drive away.
U.S. Pat. No. 6,900,723 to Yamanaka et al. discloses an anti-theft system for vehicles. Positional information is sent to an anti-theft service center upon receiving a theft signal. Audible warnings in the form of voices are sent to the in-vehicle audio system. However, interfacing a security system audible warning to a vehicle entertainment or sound system may be complicated, and may void a manufacturer's warranty.
In addition to the vehicle security functions, another type of detected vehicle condition may include a vehicle speed exceeded condition. A weak speed exceeded notification may do little to deter the driver from speeding. For example, a text display or other stand-alone audio output may not be sufficiently effective in causing a reduction in speed.